<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        #login{
            width: 350px;
            height: 250px;
            border: 1px solid #ccc;
            background: pink;
            position: absolute;
            top:0;
            left: 0;
            right: 0;
            bottom: 0;
            margin: auto;
        }
    </style>
</head>
<body>
<a href="https://www.baidu.com"></a>
<div id="login"></div>
</body>
</html>